Related Material — 69.3% match
based on chemical composition and mechanical property overlap.
GB/T 699 65 (GB/T 699:2015) and GB/T 699 55 (GB/T 699:2015) are both steel grades.
Both fall under the Carbon Steel category.
GB/T 699 65 is typically used for hot-rolled or forged quality carbon structural steel bars up to 250 mm, while GB/T 699 55 is commonly used for used for springs, wear plates, shafts, rollers, high-strength pins, and machine tools..
GB/T 699 65 is defined under Guobiao Standards (GB/T), originating from China, while GB/T 699 55 is defined under Guobiao Standards (GB/T), originating from China.
As per chemical composition, GB/T 699 65 vs GB/T 699 55 is a 91.4% match.
As per mechanical properties, the match is 25%.
Combined, this makes them a related material overall at 69.3%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
GB/T 699 65
GB/T 699 55
Tensile Strength
>=695 MPa
>=645 MPa
Yield Strength
>=410 MPa
>=380 MPa
Elongation
>=10%
>=13%
Hardness
<=255 HB (as delivered, not heat treated)
<=255 HB (as delivered, not heat treated)
Condition
Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state
Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state
Typical Applications
GB/T 699 65
Hot-rolled or forged quality carbon structural steel bars up to 250 mm
GB/T 699 55
Used for springs, wear plates, shafts, rollers, high-strength pins, and machine tools.
Can GB/T 699 65 Be Substituted With GB/T 699 55?
GB/T 699 65 and GB/T 699 55 share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.
What is the difference between GB/T 699 65 and GB/T 699 55?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can GB/T 699 65 be substituted with GB/T 699 55?
GB/T 699 65 and GB/T 699 55 share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.